Work pieces, such as containers which have been conveyed at high speed through processing steps such as filling are, by the present invention, conveyed to and from yet another station where they may be weighed, for example.
Checkweighers require only short rest periods for weighing containers since no other operations, such as partial or complete filling of a product is required.
Short rest periods require few load cells so that it is possible to arrange these in a straight line, rather than in the circular pattern required for machines with a larger number of load cells.
A straight line machine in which the load cells are in a straight line requires a unit mechanism for each load cell. Since all units with their respective load cells are supplied containers by the same conveyor, the removal of the containers from the load cells has to be done with another conveyor to avoid interference between incoming and outgoing containers.
This condition limits for all practical purposes a unit to one load cell, but each unit can be equipped with one, two or even three guides.
Since the removal of the containers from the load cell cannot be done with a similar mechanism as is used for the transfer of the containers from the supply conveyor to the load cell, a different mechanism, such a plow, can be used since this transfer does not require great accuracy.